Rhododendron plant named ‘Christine Siena’

ABSTRACT

A new cultivar of  Rhododendron  plant named ‘Christine Siena’ that is characterized by dark shiny green leaves, large red flowers, vigorous growth and flowers that last longer than 3 weeks.

Botanical designation: Rhododendron simsii.

Variety denomination: ‘Christine Siena’.

BACKGROUND OF THE INVENTION

The present invention relates to a new and distinct cultivar of Rhododendron plant botanically known as Rhododendron simsii and hereinafter referred to by the cultivar name ‘Christine Siena’.

‘Christine Siena’ was discovered as a natural branch mutation of the parent plant Rhododendron ‘Christine Magic’ (U.S. Plant Pat. No. 15,096). ‘Christine Siena’ was discovered in March of 2000 in a cultivated area of Moerbeke, Belgium.

Asexual reproduction of the new cultivar ‘Christine Siena’ by cuttings was first performed in October of 2000 in Moerbeke, Belgium. Since that time, under careful observation, the unique characteristics of the new cultivar have been uniform, stable and reproduced true to type in successive generations of asexual reproduction.

SUMMARY OF THE INVENTION

The following represent the distinguishing characteristics of the new Rhododendron cultivar ‘Christine Siena’. These traits in combination distinguish ‘Christine Siena’ as a new and distinct cultivar apart from all other existing varieties of Rhododendron known to the inventor.

-   -   1. Rhododendron ‘Christine Siena’ exhibits dark shiny green         leaves.     -   2. Rhododendron ‘Christine Siena’ exhibits large red flowers.     -   3. Rhododendron ‘Christine Siena’ exhibits vigorous growth.     -   4. Rhododendron ‘Christine Siena’ exhibits flowers lasting 3 or         more weeks.

The new cultivar ‘Christine Siena’ is distinguishable from the parent Rhododendron ‘Christine Magic’ by the following characteristics:

-   -   1. ‘Christine Siena’ has red 45C colored flowers. The flowers of         ‘Christine Magic’ are colored red 43D and 39B.

The closest comparison cultivar is the parent plant ‘Christine Magic’.

BRIEF DESCRIPTION OF THE DRAWING

The accompanying photograph illustrates the distinguishing traits of Rhododendron ‘Christine Siena’. The plant in the photograph shows an overall view of a 24 month old plant. The photograph was taken using conventional techniques and although colors may appear different from actual colors due to light reflectance it is as accurate as possible by conventional photographic techniques.

BOTANICAL DESCRIPTION OF THE PLANT

The following is a detailed description of the new Rhododendron cultivar named ‘Christine Siena’. Data was collected in Kruishoutem, Belgium from 24 month old greenhouse grown plants in 1.0 liter containers. The time of year was Fall and the average temperature was 20° Centigrade during the Summer and 4° Centigrade during the Winter. The light level was natural outdoor light and there were no photoperiodic treatments. OSMOCOTE® and NPK were applied. Color determinations are in accordance with The Royal Horticultural Society Colour Chart 2001 edition, except where general color terms of ordinary dictionary significance are used. The growing requirements are similar to the species. ‘Christine Siena’ has not been tested under all possible conditions and phenotypic differences may be observed with variations in environmental, climatic, and cultural conditions, however, without any variance in genotype.

-   Botanical classification: Rhododendron ‘Christine Siena’. -   Use: Ornamental Perennial. -   Parentage: ‘Christine Siena’ is a natural branch mutation of     Rhododendron simsii ‘Christine Magic’. -   Vigor: Moderate. -   Growth rate: Approximately 8 to 15 cm. per year. -   Growth habit: Broad upright, densely branched. -   Plant shape: Flattened globular. -   Suitable container size: 1.0 liter container. -   Height: Average 25 cm. in height. -   Width: Average 41 cm. in width. -   Hardiness: USDA Zone 9. -   Propagation: Cuttings. -   Time to initiate roots: Approximately 30 days to produce roots on an     initial cutting. -   Time to produce a rooted cutting or liner: Approximately 60 days. -   Root system: Fine and fibrous. -   Stem:     -   -   Branching habit.—Freely branching.         -   Average number of lateral branches.—15.         -   Pinching.—Yes.         -   Lateral branch diameter.—3 cm. in diameter.         -   Lateral branch length.—9 cm. in length.         -   Lateral branch strength.—Moderately strong.         -   Stem color.—144B, older stems 200C to 200D.         -   Pubescence.—Dense, length 1.5 mm, color 175C to 175D.         -   Internode length.—7 mm. between nodes.         -   Shape.—Round.         -   Surface.—Dull.         -   Stem strength.—Moderately strong. -   Foliage:     -   -   Texture.—Glossy, slightly leathery.         -   Leaf arrangement.—Alternate, clustered towards the top of             the stems.         -   Compound or single.—Single.         -   Quantity of leaves per lateral branch.—20.         -   Leaf shape.—Elliptic to obovate.         -   Leaf apex.—Mucronulate.         -   Leaf base.—Attenuate.         -   Leaf length.—3.6 cm. in length.         -   Leaf width.—1.8 cm. in width.         -   Pubescence.—Slight, both sides, length 1 mm, color             gray-orange 175C to 175D.         -   Leaf margin.—Entire.         -   Vein pattern.—Pinnate.         -   Young leaf color (upper surface).—Between 141A and 143A.         -   Young leaf color (lower surface).—138A to 138D.         -   Mature leaf color (upper surface).—Between 139A and N189A.         -   Mature leaf color (lower surface).—137B.         -   Vein color (lower surface).—143A.         -   Vein color (upper surface).—143C.         -   Leaf attachment.—Petiolate.         -   Petiole dimensions.—6 mm in length, 2 mm. in width, 1 mm in             height.         -   Petiole color.—143C.         -   Durability of foliage to stress.—Moderate. -   Flower:     -   -   Flower arrangement: Terminal clusters.         -   Inflorescence type.—Semi-double.         -   Inflorescence dimensions.—10.5 cm. in diameter and 5.5 cm.             in height.         -   Flowering habit.—Continuously once a year.         -   Quantity of flowers per lateral stem.—Approximately 5.         -   Quantity of flower buds per lateral stem.—Approximately 5.         -   Quantity of flowers and buds per plant.—Approximately 300.         -   Flowering season.—Late winter to early summer.         -   Time to flower or response time.—9 months.         -   Rate of flower opening.—After the first flower of a cluster             has opened, all flowers of that cluster will open in             approximately 14 days.         -   Fragrance.—None.         -   Self-cleaning or persistent.—Self-cleaning.         -   Flower bud length.—9 mm. in length.         -   Flower bud diameter.—7 mm. in diameter.         -   Flower bud shape.—Ovate.         -   Bud color.—45D.         -   Rate of bud opening.—10 days.         -   Flower aspect.—Upright to outward.         -   Flower shape.—Funnelform.         -   Flower dimensions.—5.5 cm. in diameter and 3.7 cm. in             height.         -   Flower longevity.—Lasts approximately 24 days on plant.         -   Petal appearance.—Dull, slight velvety.         -   Petal texture.—Glabrous.         -   Petal arrangement.—Funnelform, petals placed rotate.         -   Number of petals.—Five in number.         -   Petals fused or unfused.—Lower 33% fused.         -   Petal shape.—Irregular obovate.         -   Petal margin.—Entire, slightly wavy.         -   Petal apex.—Rounded to praemorse.         -   Petal dimensions.—3.9 cm. in length and 2.2 cm. in width.         -   Petal color when opening (upper side).—45C.         -   Petal color when opening (under side).—45C.         -   Petal color when fully opened (upper side).—45C.         -   Petal color when fully opened (under side).—45C.         -   Petal color fading to.—Not fading.         -   Petaloid appearance.—Dull, slightly velvety.         -   Petaloid arrangement.—Rotate, in the center of the flower.         -   Petaloid number.—5 in number.         -   Petaloid shape.—Irregular, obovate to narrow obovate.         -   Petaloid margin.—Entire.         -   Petaloid dimensions.—3.8 cm. in length and 1.9 cm. in width.         -   Petaloid color immature.—45C.         -   Petaloid color mature.—45C. -   Calyx:     -   -   Calyx shape.—Campanulate.         -   Calyx dimensions.—1.1 cm. in length and 1.8 cm. in diameter. -   Sepals:     -   -   Sepal appearance.—Dull, pubescent.         -   Sepal arrangement.—Campanulate.         -   Number of sepals.—Five in number.         -   Sepals fused or unfused.—Lower 20% fused.         -   Sepal shape.—Ovate.         -   Sepal margin.—Entire.         -   Sepal apex.—Acute.         -   Sepal base.—Fused into campanulate calyx.         -   Sepal dimensions.—1.1 cm. in length and 5 mm. in width.         -   Sepal color when opening (upper side).—145C.         -   Sepal color when opening (under side).—145C.         -   Sepal color mature (upper side).—145B to 145C.         -   Sepal color mature (under side).—145B to 145C. -   Bracts:     -   -   Number of bracts.—5 in number.         -   Bract dimensions.—1.2 cm. in length and 7 mm. in width.         -   Bract shape.—Ovate.         -   Bract apex.—Acute.         -   Bract pubescence.—Sparse on under side, length 1.5 mm, color             175C to 175D.         -   Bract color (both sides).—144A to 144B. -   Pedicels:     -   -   Pedicel dimensions.—1.4 cm. in length and 2.5 mm. in             diameter.         -   Pedicel angle.—75°.         -   Pedicel color.—47C with a base 145C to 145D.         -   Pedicel strength.—Moderate. -   Reproduction organs:     -   -   Stamen.—None.         -   Pistil number.—1 in number.         -   Pistil dimensions.—1.8 cm. in length.         -   Stigma shape.—Club shaped, flattened at the top.         -   Stigma color.—53A.         -   Style length.—1.75 cm.         -   Style color.—47A.         -   Ovary color.—138A to 138B. -   Seed: Seed production has not been observed. -   Disease and pest resistance: Plants of the new Rhododendron have not     been observed for disease or pest resistance. 

1. A new and distinct variety of Rhododendron plant named ‘Christine Siena’ as described and illustrated. 